日粮代谢能水平对AA肉种鸡产蛋后期蛋组分影响

Effect of dietary metabolic energy levelson egg component of AA broilers during late laying period

选用49周龄AA肉种鸡270羽,随机分为3组,分别饲喂3个代谢能水平日粮ME 1、ME 2、ME 3(14.04、11.70和9.36 MJ·kg-1),每组6个重复,每个重复15羽。每日投料量和日粮中粗蛋白质、氨基酸等其他营养水平均相同。在肉种鸡50周龄时正式开始试验,试验期为10周。结果表明,在肉种鸡产蛋后期(50～60周龄),①与ME 2组相比,ME 1组中蛋重极显著降低(P<0.01),55周龄蛋黄粗脂肪含量和60周龄粗蛋白含量显著提高(P<0.05)。ME 3组中60周龄蛋黄粗脂肪含量极显著降低(P<0.01)。②与ME 1组相比,ME 3组显著降低55周龄蛋黄相对重(P<0.05),极显著减少60周龄蛋黄相对重(P<0.01)。ME 3组蛋黄颜色、蛋黄/蛋清极显著降低(P<0.01)。③随日粮代谢能水平降低,蛋合格率、蛋清相对重、蛋壳厚度、蛋壳相对重无显著变化(P>0.05)。④日粮代谢能水平对肉种鸡产蛋后期破蛋率、蛋壳强度、蛋形指数没有影响(P>0.05)。综上所述,在肉种鸡产蛋后期,日粮代谢能降低至9.36 MJ·kg-1时,对肉种鸡产蛋性能无不良影响,对蛋清、蛋壳及其营养物质没有影响,但可以显著降低蛋黄中脂肪沉积。

A total of 270, 49-week-old AA broilers with similar body weight were divided randomly into 3 ME levels ME 1, ME 2, ME 3（14.04, 11.70 and 9.36 MJ. kg-1）with 6 replicates of 15 broilers each. In addition to the energy level, nutritional levels of intake were the same in each group. The experiment was started at 50-week-old, and lasted for 10 weeks. The results showed that during the late laying pedod （50 to 60 weeks age） of AA broilers, ①Compared with the ME 2, egg weight was significantly lowered in ME 1 group （P〈0.01）. The 55-week-age contents of crude fat and the 60-week-age contents of crude protein in yolk of ME 1 group were significantly increased （P〈0.05）, the 60-week-age content of crude fat in yolk of ME 3 was markedly increased （P〈0.01）. ② Compared with the ME 1, the relative weight of yolk in ME 3 was notably higher at 55 weeks of age （P〈0.05） and at 60 weeks of age （P〈0.01）. The yolk color score and theratio of egg yolk and white in ME 3 were notably lowered （P〈0.01）. ~ With the decline of energy in breeders＇ diets, there were no notable effects of dietary metabolic energy level on the qualified egg rate, the relative weight of egg white, the relative weight of eggshell and Eggshell thickness （P〉0.05）. ③ No effect of dietary metabolic energy levels on the crack egg rate, Eggshell strength and Egg shape index were found （P〉0.05）. In conclusion, There were no worse effect on laying performance, egg white and eggshell when the dietary metabolic energy level decreased to 9.36 MJ. kg1. On the other hand, the fat deposition in egg yolk of AA broilers was decreased during the late laying period.